1 Terry: {reading a book on the flight} This says the Tibetan name for the yeti is "migou", which Lovecraft rendered as "Mi-go" in his 1930 story The Whisperer in Darkness.2 Terry: He describes the "Abominable Snow-Men" of the Himalaya as pinkish things with crustaceous bodies, membranous wings, and a convoluted ellipsoid where a head should be.3 Terry: These fungoid abominations extract living brains and come from the "dark planet Yuggoth", which he identifies as the then newly discovered planet Pluto...4 Steve: Crikey! We better be careful. That "Pluto is a planet" crowd can get stroppy!

Lovecraft set up Yuggoth as a mysterious dark planet beyond the edge of the solar system - which up until 1930 was considered to end at the last
known planet, Neptune. The discovery of Pluto in 1930 gave us a ninth planet, and served as one of the inspirations for The Whisperer in Darkness,
as Lovecraft sets up the mystery of an unidentified ninth planet early in the story, and then postulates that the recent discovery of Pluto perhaps confirms the
incredible horrors that he has described in the story up to that point.

The Mi-go themselves are basically as Terry describes them. They are strange fungoid beings with hard crustacean-like carapaces, large bat-like
wings, a strange fleshy appendage covered in antennae instead of a head, and so on. Which is kind of odd, given that Lovecraft explicitly identifies them
with the Migou, which is the Tibetan name for the yeti. As far as I know, no traditional Himalayan
accounts of the yeti refer to them as fungus-beings from Pluto with wings and exoskeletons.

Someone must be hiding something...

Anyway, since 1930 we've lived in a solar system containing nine planets. No doubt almost everyone reading this learnt at school that there are
nine planets in our solar system. Of course, what is a planet is a matter of definition, and this year (2006) the
International Astronomical Union decided that the definition of what was
and what was not a planet needed to revisited, following the recent discoveries of several Pluto-like objects orbiting in the deep solar system.
The crunch came with the discovery of Eris, which is larger than Pluto.

It has become clear that Pluto is not unique in any sense. There is a large population of roughly Pluto-sized bodies of similar composition orbiting the
Sun at similar distances. The options were either:

Call all these things planets, since they are like Pluto and Pluto has been called a planet for over 75 years. This would mean we would now have
something like a dozen known planets, and the certain knowledge that there are dozens if not hundreds of other planets that we haven't yet discovered.

Don't call these things planets, but leave Pluto as a planet because of tradition, leaving us with our familiar nine planets.

Change the meaning of "planet" to exclude Pluto, Eris, and all the hundreds of other things out there that are just like them.

Each option has advantages, disadvantages, adherents, and detractors. A large fraction, perhaps even a majority, of the general public held a strong
emotional attachment to Pluto being a planet. This is only natural, as nobody likes being told that what they learnt at school was wrong. That means
that a lot of people supported either option 1 or 2 above.

From a scientific viewpoint, option 1 is undesirable, because it changes what was considered a fundamental property of planets - that they are
relatively rare objects in a solar system, of primary importance after the Sun itself. Whatever way you look at it, Pluto, Eris, and their band of
friends are not of similar importance to solar system studies as the big eight planets. They form a little group of objects of their own, known as
Kuiper Belt Objects. Or not such a little group; over 800 are known so far, and many thousands more
are expected to be out there.

Option 2 is incompatible with a consistent set of definitions that can apply to all objects. You can't say that all oranges are oranges, except for
this one, which is not different from any other orange, except that we call it an apple. Well, you can, but it doesn't make much sense.

Which left option 3. The unpopular option.

So the IAU redefined what a planet is. Pluto is no longer considered a planet.
We have eight planets again. And there are quite a few people who are actively angry about that decision.

The Mi-go are probably among them.

2016-08-02 Rerun commentary: Given it's now almost ten years since this comic was first published, it's quite possible that there are now people reading it who learnt at school that there are eight planets and that Pluto is a member of the classes of dwarf planets and Kuiper belt objects.